Cassandra集群管理-节点异常重启
登陆一台集群节点，直接重启服务器(172.20.101.166)，设置了 cassandra 开机启动。
注意:
本文档只是体系文档中的一部分，前面文档信息详见：
测试准备+下线正常节点：https://blog.51cto.com/michaelkang/2419518节点异常重启：https://blog.51cto.com/michaelkang/2419524添加新节点：https://blog.51cto.com/michaelkang/2419521删除异常节点：https://blog.51cto.com/michaelkang/2419525
场景：
节点被异常重启，对集群引发的反应。
cassandra.log 基本没有输出
tailf /var/log/cassandra/cassandra.log
system.log
有明显日志报 172.20.101.166 DOWN ！！！
172.20.101.165 节点：
[root@kubm-03 lib]# tailf /var/log/cassandra/system.log
INFO [GossipStage:1] 2019-07-11 18:19:23,372 Gossiper.java:1026 - InetAddress /172.20.101.166 is now DOWN
查看异常节点
[root@kubm-01 ~]# nodetool describecluster
Cluster Information:
Name: pttest
Snitch: org.apache.cassandra.locator.GossipingPropertyFileSnitch
DynamicEndPointSnitch: enabled
Partitioner: org.apache.cassandra.dht.Murmur3Partitioner
Schema versions:
cfce5a85-19c8-327a-ab19-e1faae2358f7: [172.20.101.164, 172.20.101.165, 172.20.101.167, 172.20.101.160, 172.20.101.157]
UNREACHABLE: [172.20.101.166]
debug.log
大量报无法连接 172.20.101.166
172.20.101.164 节点：
tailf /var/log/cassandra/debug.log
DEBUG [GossipStage:1] 2019-07-11 18:19:23,374 OutboundTcpConnection.java:205 - Enqueuing socket close for /172.20.101.166
DEBUG [MessagingService-Outgoing-/172.20.101.166-Small] 2019-07-11 18:19:23,374 OutboundTcpConnection.java:411 - Socket to /172.20.101.166 closed
DEBUG [GossipStage:1] 2019-07-11 18:19:23,374 OutboundTcpConnection.java:205 - Enqueuing socket close for /172.20.101.166
DEBUG [MessagingService-Outgoing-/172.20.101.166-Gossip] 2019-07-11 18:19:23,374 OutboundTcpConnection.java:411 - Socket to /172.20.101.166 closed
DEBUG [GossipStage:1] 2019-07-11 18:19:23,374 FailureDetector.java:313 - Forcing conviction of /172.20.101.166
DEBUG [MessagingService-Outgoing-/172.20.101.166-Gossip] 2019-07-11 18:19:24,740 OutboundTcpConnection.java:425 - Attempting to connect to /172.20.101.166
INFO [HANDSHAKE-/172.20.101.166] 2019-07-11 18:19:24,741 OutboundTcpConnection.java:561 - Handshaking version with /172.20.101.166
DEBUG [MessagingService-Outgoing-/172.20.101.166-Gossip] 2019-07-11 18:19:24,742 OutboundTcpConnection.java:533 - Done connecting to /172.20.101.166
验证查询
系统启动后，服务自然启动，能正常加入集群。
cassandra@cqlsh> SELECT * from kevin_test.t_users;
user_id | emails | first_name | last_name
---------+---------------------------------+------------+-----------
6 | {'k6-6@gmail.com', 'k6@pt.com'} | kevin6 | kang
7 | {'k7-7@gmail.com', 'k7@pt.com'} | kevin7 | kang
9 | {'k9-9@gmail.com', 'k9@pt.com'} | kevin9 | kang
4 | {'k4-4@gmail.com', 'k4@pt.com'} | kevin4 | kang
3 | {'k3-3@gmail.com', 'k3@pt.com'} | kevin3 | kang
5 | {'k5-5@gmail.com', 'k5@pt.com'} | kevin5 | kang
0 | {'k0-0@gmail.com', 'k0@pt.com'} | kevin0 | kang
8 | {'k8-8@gmail.com', 'k8@pt.com'} | kevin8 | kang
2 | {'k2-2@gmail.com', 'k2@pt.com'} | kevin2 | kang
1 | {'k1-1@gmail.com', 'k1@pt.com'} | kevin1 | kang
测试结果：
反复重启节点，查询表内容正常。
